A gas turbine engine generally includes a fan and a core arranged in flow communication with one another. The core of the gas turbine engine generally includes, in serial flow order, a compressor section, a combustion section, a turbine section, and an exhaust section. With multi-shaft gas turbine engines, the compressor section can include a high pressure compressor (HP compressor) and a low pressure compressor (LP compressor), and the turbine section can similarly include a high pressure turbine (HP turbine) and a low pressure turbine (LP turbine). With such a configuration, the HP compressor is coupled with the HP turbine via a high pressure shaft (HP shaft), and the LP compressor is coupled with the LP turbine via a low pressure shaft (LP shaft).
In operation, at least a portion of air over the fan is provided to an inlet of the core. Such portion of the air is progressively compressed by the LP compressor and HP compressor until it reaches the combustion section. Fuel is mixed with the compressed air and burned within the combustion section to provide combustion gases. The combustion gases are routed from the combustion section through the HP turbine and LP turbine. The flow of combustion gasses through the turbine section drives the HP turbine and the LP turbine, each of which in turn drive a respective one of the HP compressor and the LP compressor via the HP shaft and LP shaft. The combustion gases are then routed through the exhaust section, e.g., to atmosphere.
In addition to driving the LP compressor, the LP shaft can additionally drive the fan through a fan gearbox. The gearbox allows the LP shaft to be rotated at a higher speed relative to the fan for greater efficiency. Certain gas turbine engines additionally include an actuation assembly operable with a plurality of fan blades of the fan to change a pitch of each of the plurality of fan blades to further increase an efficiency of the fan.
It can be difficult to package the actuation assembly in the fan due to, e.g., a positioning of one or more bearings that facilitate rotation of the plurality of fan blades. The one or more bearings are positioned inward along a radial direction to minimize a rotational speed to which they are exposed. Accordingly, a fan for a gas turbine engine that allows for packaging of the pitch change mechanism within the fan would be useful.